Compare each chunk of large objects when uploading

Previously, we compared the ETag from Swift against the MD5 of the
entire large object. However, the ETag for large objects is generally
the MD5 of the concatenation of the ETags for each segment, unless the
object is a DLO whose segments span more than one page of a container
listing. Rather than worry about ETags, just compare each chunk of the
segmented file. This allows the use of --skip-identical when uploading
SLOs and DLOs.

Additionally, there are several test-related improvements:
 * The default arguments for OutputManager are now evaluated on
   construction, rather than on definition, so that
   TestOutputManager.test_instantiation will succeed when using nosetest
   as a test runner. (See also: bug 1251507)
 * An account_username option is now available in the functional tests
   config file for auth systems that do not follow the account:username
   format.
 * CaptureOutput no longer writes to the captured stream, and
   MockHttpTest now captures output. These were polluting test output
   unnecessarily. (See also: bug 1201376)

Change-Id: Ic484e9a0c186c9283c4012c6a2fa77b96b8edf8a
Closes-Bug: #1201376
Closes-Bug: #1379252
Related-Bug: #1251507

1 files changed, 8 insertions, 1 deletions

diff --git a/tests/unit/utils.py b/tests/unit/utils.py
index 88d6d12..bb68f4f 100644
--- a/tests/unit/utils.py
+++ b/tests/unit/utils.py
@@ -207,6 +207,12 @@ class MockHttpTest(testtools.TestCase):
         self.fake_connect = None
         self.request_log = []
 
+        # Capture output, since the test-runner stdout/stderr moneky-patching
+        # won't cover the references to sys.stdout/sys.stderr in
+        # swiftclient.multithreading
+        self.capture_output = CaptureOutput()
+        self.capture_output.__enter__()
+
         def fake_http_connection(*args, **kwargs):
             self.validateMockedRequestsConsumed()
             self.request_log = []
@@ -367,6 +373,7 @@ class MockHttpTest(testtools.TestCase):
         # un-hygienic mocking on the swiftclient.client module; which may lead
         # to some unfortunate test order dependency bugs by way of the broken
         # window theory if any other modules are similarly patched
+        self.capture_output.__exit__()
         reload_module(c)
 
 
@@ -392,7 +399,7 @@ class CaptureStream(object):
         self.stream = stream
         self._capture = six.StringIO()
         self._buffer = CaptureStreamBuffer(self)
-        self.streams = [self.stream, self._capture]
+        self.streams = [self._capture]
 
     @property
     def buffer(self):